test/ruby/test_symbol.rb: tests for [Bug #8531]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@41343 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
skip new tests until fixed

* test/ruby/test_proc.rb, test/ruby/test_symbol.rb: skip new tests
  until fixed, for the time being.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@41344 b2dd03c8-39d4-4d8f-98ff-823fe69b080e